Abstract The services in the Mouse Metabolic Phenotyping Core (Core C) draw upon the expertise of many investigators at UTSW to provide comprehensive analytical capabilities that are on par with the best facilities in the world. We are looking back on 5 successful years during which we have expanded our assay capabilities and supported Projects 1 through 3 during the ongoing funding period with our comprehensive phenotyping panel under the direction of Dr. Jay Horton. We have made major steps towards establishing a state-of-the-art sphingolipidomics suite beyond the originally described standard phenotyping panel. The availability of standardized assays speeds the pace of our research, facilitates inter-lab comparisons of data, and provides a common platform for the necessary close interactions between investigators. Animal models that allow careful characterization of the metabolic effects of obesity and that have an altered communication axis between the three critical tissues studied here are vital to understand the pathogenesis of disease. Given the number of phenotypic measurements, the range of target metabolites, and the number of different animal models investigated, it is necessary to provide uniform measurements and to have quality control guidelines in place. To facilitate the research for Projects 1-3, Core C will provide comprehensive, state-of-the-art measurements of multiple parameters, with measurements involving mass spectrometry and physiological read outs that include lipid, glucose, and metabokine assays. The technical expertise Core C offers will bring multiple benefits to project investigators, including the following: ? Centralized Core services are more cost effective and prevent the duplication of reagents across PPG investigators. ? Provides consistency in various assays across laboratories. ? Provides consistent quality control measures. ? Makes available technically challenging assays, such as hyperinsulinemic-euglycemic clamps, that cannot be established in individual laboratories. ? Frees investigators from routine work to focus on the intellectual challenges of the projects.